This camera contains a high definition 640×480 pixel detector
that allows temperature readings either in real time or from a stored image. It
has a 0.04°C sensitivity and ±1°C accuracy. The primary advantage of this
platform is that large areas can be surveyed with precision.

This provides a resolution of a little less than the 352 x 288 pixel,
conventional Pencam
image of Cairnpapple, taken by James Gentles
in 2003. The sensitivity of the camera is 0.1°C but it is not calibrated
for temperature readout. The advantage of our system is that it is relatively
cheap and light. However, the total weight of the prototype rig (including camera) is 1.5kg!

Cade and John with the sandwich
box housed thermal camera and KAP rig.

AVI still

Our first KAT image. John on wet
grass at night.

10 Sept 2011 (HQ Flowform 2.0 kite)

Few aerial images are as boring
as this, except possibly our first KAP
image.

Half frame crop of image from the new PVR, 23 September
2011.
(MP4 still)

The price of this
camera is outside the remit of our normally cost-conscious work. However, we
expect the price (and weight) of handheld, thermal imagers to continue to fall in
the near future.

For simplicity, we considered
the available
handheld, thermal IR units, but none offered this resolution,
robustness and
field of view, at this price (August 2011).

Is such an approach a useful
and viable option for archaeological KAP, as the
near
infra-red has already proved to be? That is the question
we hope to answer. The two main considerations are (1) The
slow speed of capture of individual frames and (2) The
optimal environmental conditions for camera deployment.

A HQ FF4.0 kite has been
purchased
to cope with the rig over a wider range of wind speeds. We also have
a Power Sled 81, but we are more trusting of the consistency of performance of
HQ flow forms in strong winds. Although we have not lost a camera
since we started KAP in 2007, infrequently, sleds can shear out of the sky.
Normally, this is not a problem, but it would be a disaster and
dangerous with a £2k, 1.5kg payload.

To reduce weight, the 60w input
voltage stabiliser
(235g) has been replaced with one rated at ~10w (22g).
Specifications:

Input Voltage:11.5
to 35.0 Volts

Output Voltage:10
Volts+/-5%

Line regulation:10
mV(typical)

Load Regulation:12
mV(typical)

Operating temperature:0
to 125°C

Storage
temperature: -
65 to 150°C

The unit (CCVS3 from e-bay)
hasthermal overload and short
circuit protection.

Moisture-proof
enclosure.

Several
off-the-shelf voltage stabilisers are available for around £10 each. These are
solid state replacements for electro-mechanical devices used on
older cars to regulate the voltage to the control panel. The
4800mAh battery (176g) has also been replaced with a smaller one rated at
1800mAh (80g). The PVR (149g) has been replaced with a smaller,
lighter model (82g). The total weight of the rig is now 1.16kg.

The camera is now
ready for
archaeological field trials, which will be carried out by
group members John, Jim and Rosie.

We have lost the best
part of the year for crop work
(Kiescow
pdf). However, we will continue
to image sites thermally, especially to see if anything
new appears at locations which we have already
photographed in the visible and near infra-red parts of
the spectrum.

Kite aerial
thermography is not an easy technique. We have a
long way to go before we will know if the effort and
expense is worthwhile archaeologically......but it is looking
very promising.